1. Field of the Invention
This invention relates to the dispensing of liquids, and more particularly it has to do with the dispensing of beverages provided in a keg or barrel, such as (possibly) cola or soda, or (more likely) ale or beer. Both in commercial establishments (bars and taverns) and in private clubs and homes, there repeatedly arises the problem of gauging, from time to time, how much liquid still remains in a particular barrel or keg. The present invention has as an object the solving of that problem in a manner which is especially convenient and inexpensive, so much so that the invention may find use wherever beverages on tap are being dispensed, whether in commerce or in the home.
2. Description of the Prior Art
There exist, as a background for this invention, all the present practices concerning the dispensing of liquids, especially liquid beverages, and most especially beer.
Beer is commonly provided not only in cans or bottles of various sizes (the 7-ounce pony bottle, the standard 12-ounce bottle or can, and the larger 16-ounce and even 24-ounce bottle or can, and the 32-ounce quart and even larger 40-ounce bottles) but also in aggregates of these (six-packs of cans or bottles and 24-unit cases) and in single glasses (smaller or larger) or pitcher (also smaller or larger) drawn from a keg.
The "barrel", when used as a term for a unit of capacity, refers to quite a large quantity of liquid, namely, 31.5 gallons. Any keg containing one barrel of beer would be too heavy to be handled at all conveniently by most persons: the weight of beer, per unit of volume, is not substantially different from that of water, which can be stated in various ways: 1 gram per cubic centimeter, 62.4 pounds per cubic foot, 8.3 pounds per gallon, or about 265 pounds per barrel. In commerce, we have quarter-barrel and half-barrel kegs, which are of more manageable weight and size, containing as they do about 651/2 and 133 pounds of beer, respectively. The "quarter" (a quarter-barrel keg) contains a quantity of beer equal to that in three and a half (31/2) cases of 12-ounce bottles or cans, with 24 cans or bottles to the case. The "half" (a half-barrel keg) corresponds to seven (7) cases of 12-ounce bottles or cans.
The kegs currently in use for dispensing beer are, nowadays, most commonly pressurized by means of a source of carbon-dioxide gas which is supplied, via a pressure-regulator, to exert upon the beer some known and predetermined and suitable degree of super-atmospheric pressure, such as 8 lbs. per square inch gage. The rate of flow of the beer or other liquid contained in a keg through the tap, when its valve is open, is proportionate to the super-atmospheric pressure that is so exerted upon the liquid contained in the keg.
It is also properly a part of the background of the present invention that it is known that when a keg is provided with a gas pressure of 8 pounds per square inch gage, it takes approximately 8 seconds to fill a 12-ounce glass of beer, which works out to an aggregate pouring time of something like 3 minutes and 12 seconds (3:12) for the quantity of beer contained in a case of 24 bottles or cans, or then, in the case of a "quarter", 11 minutes and 12 seconds, and in the case of a "half", 22 minutes and 24 seconds.
The problem of arriving at a display of the quantity of liquid remaining in a keg is an old one, and in general, the known answers to it have been unsatisfactory, largely from not only the size but also the expense and inconvenience of the equipment needed for the purpose.
It has long been apparent, for example, that the keg may be mounted upon some means for weighing it, with there also being provided some operative connection from the weighing means to a means for displaying the current weight at a location easily seen by the person operating the tap. There would be no reason, with such equipment, to insist that the display concerning the beer remaining be located within the tap handle, but it would need to be put somewhere about the work area, and electric lines need to be run to it, and there is the problem that the weighing means needs to be sturdy enough to withstand having quarter- or half-barrel kegs of beer repeatedly loaded on to it and removed from it. It is understandable that there has been no widespread adoption of any such idea.
As will be explained below, the present invention involves a tap handle, a display means located therein, a power source, a microprocessor which has timing capability or some associated independent timer means, and a position-sensitive switch, such as a mercury switch. Tap handles are known. Display means are known, both in general and in a small size, suitable for being contained in the face portion of a tap handle. Power sources (batteries) small enough to be contained in a tap handle are known. Microprocessors are known. Mercury switches per se are known in general. Thus, the particular individual components of apparatus required for the practice of the present invention are not, per se, novel. The combination, however, of a mercury or other position-sensitive switch plus a surrounding tap handle, alone or with the other associated equipment provided in accordance with the present invention, is believed to be novel and unobvious, as is also the idea of combining such equipment as a way of providing a solution to the particular problem which the present invention addresses.